My new december LSAT score came in and it's a bit higher, not lower, thankfully.

I can't figure out if it's assumed I will be sending an addendum in. I was panicky during the first LSAT and not feeling well physically. I performed below my PT average, and this second time around I barely prepared, felt better, and performed better. Is it worth mentioning that "officially" in an addendum?

On a related note, don't schools tend to take the highest score? Because this seems deeply related to that question. I can't figure out why to even bother sending an addendum unless they truly consider both scores and the average.